<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>分组选择器</title>
</head>

<body>
    <style>
        h1,
        h2,
        p {
            text-align: center;
            color: red;
        }
    </style>

    <h1>Hello World!</h1>
    <h2>更小的标题</h2>
    <p>这是一个段落。</p>


</body>

</html>